1. Field of the Invention
The present invention relates to exercise apparatuses, and more particularly, to an exercise apparatus that generates an elliptical exercise track.
2. Description of the Related Art
To modern people who live a busy life with less opportunity and time to do exercise, it is important to keep healthy by taking exercise regularly. Thus, indoor exercise equipment is popular in both houses and fitness clubs for its availability and accessibility.
Since walking has been medically proven as a moderate and relaxing exercise suitable to average people, exercise equipment related thereto, such as fitness steppers and cross trainers, is taking a significant market share. However, a stepper only facilitates a simple “mark time” movement of legs. A known cross trainer trains not only lower and upper limbs, but also arms, thus being multifunctional and more interesting to exercisers.
The conventional cross trainer preliminary comprises a frame mounted thereon a pair of handle-shafts swingable backward and forward. Each said handle-shaft has an upper end provided with a handle portion and a lower end coupled with a treadle. Thereby, the alternately swing handle-shafts guide an exerciser stepping on the treadles and holding the handle portions to perform in-place striding. However, the swing handle-shafts themselves can only perform simple pendulum-like swinging and thus only a limited range of exercisers' muscles can get trained by the conventional cross trainer. For the same reason, the exercise motion guided by the conventional cross trainer is still far from genuine human striding. Besides, two treadle-shafts of the conventional cross trainer are configured to move independent of each other and are prone to get interfered by the hands' operation. During exercise, when exercising with rapidness or under uncoordinated limb movements, an exerciser may have difficulty in keeping continuity and balance and thus risks getting muscle strains or may fall down from the trainer.
U.S. Pat. No. 7,648,445 disclosed an elliptical exercise apparatus capable of simulating human striding and running and increasing muscles of exerciser's legs and feet, achieving improved exercise effect. The apparatus disclosed in the aforesaid patent can direct exerciser's legs in two counter directions, thereby preventing the exerciser's two feet from simultaneously moving forward or backward and preventing the exerciser from exercising with only one foot due to the exerciser's poor coordination. As a result, the stepping motions of exerciser's feet may be performed smoothly and continuously.
In the aforesaid patent, the elliptical exercise track is achieved by a sliding motion of a sliding treadle assembly having a treadle portion and slidably sleeved onto a lead swing arm as well as a swing motion of the lead swing arm. However, because the sliding treadle assembly occupies a certain volume with a certain weight, the exerciser must pay much effort to raise the sliding treadle assembly along the lead swing arm when the exerciser uses he/her feet to push the treadle portions of the sliding treadle assembly, resulting in that the operating motion of the apparatus becomes heavy and lumberly and the exerciser may fell slack about the operating motion while the exerciser does exercise on the apparatus. In addition, because of the sliding treadle assembly occupying a certain volume with a certain weight, the rollers installed inside the sliding treadle assembly may wear badly during reciprocally up-and-down sliding motion of the sliding treadle assembly. Therefore, a great amount of rollers need to be used inside the sliding treadle assembly for sharing heavy load so as to increase lifespan of the apparatus. In other words, the apparatus disclosed in the aforesaid patent solves the problem of the conventional cross trainer but has some drawbacks needed to be improved.